One of the most ubiquitous modifications attached to oligos is the bright green fluorophore known as Fluorescein, FITC, or FAM (Fluorescein amidite). Attaching the fluorophore to oligonucleotides is not its only use though. Read on.

The discovery of the base guanine came in 1844, when it was isolated from Peruvian guano by B. Unger. Although guanine can be referred to more precisely by other names such as 2-amino-6-hydroxypurine, no other designation is as historically descriptive.